The Universal Reset Control 374 is designed to operate all of the mechanical equipment in a residential hydronic heating system. It can be used in applications ranging from a single zone of baseboard with an on/off boiler to multiple fan coils, low temperature staple up zones, low temperature in-slab radiant zones, domestic hot water, and 2 on/off boilers. It regulates up to three space heating water temperatures through Outdoor Temperature Reset. It is capable of controlling up to 2 on/off boilers, up to 2 mixing devices (either variable speed pumps or floating action mixing valves), and Domestic Hot Water or setpoint loads.